I went to work for North American Aviation in march of 1955 as a machinist in the the shop that supported various aerospace research groups. I graduated from what is known as California State University at Long Beach (CSULB) in June of 1961. Shortly after graduation, I was promoted to the technical staff as an MTS I engineer. My Supervisor was Gerry Hardesty. I was the new kid on the block even though Gerry had been my supervisor for several years. In spite of my considerable experience as a machinist in the shop that made many parts used in numerous gyros and had several years of experience working as a technician in the Instrument laboratory, I did not know much about gyros at the engineering level. But I was asked by Gerry to help him evaluate the stability of the concrete floors in the building then nearing completion in Anaheim. That was the site of our new test laboratory. I had no idea how we were to evaluate the stability of the floors. I do not remember how it came about, but I eventually came to the understanding we were going to place a G2 gyro on the floor and use it to “measure” floor stability. The G2 was a single degree of freedom, floated gyro with a ball bearing supported rotor. It was the same model gyro that was used on the N2 system. That was the system used to guide the USS Nautilus and the USS Skate under the polar ice to the North Pole. The test gyro was operated in the rate mode, ie, a servo mechanism kept the gyro pickoff nulled by supplying a torquer current to the gyro torque coils. The magnitude of the current was proportional to the rate the gyro case was being rotated. This was our test setup. We would “evaluate” the floor “stability” by how much noise was on the signal proportional to the gyro torquer current. We rather quickly confirmed what we already suspected; normal foot traffic in the vicinity of our test sites would render the data unusable. We obviously had a problem. (This setup became one of our demonstrations we used on our family day events). The solution was anything but subtle. As I recall, it was proposed that the floor of the new laboratory be replaced with thick concrete. The new laboratory was very large and there must have been resistance to the idea that a large part of the floor area have a slab floor. In any case, what we ended up with was big; four feet thick by forty feet wide by sixty feet long bedded in dry sand. The construction of the forms and the pouring of the concrete was done after we had moved into into the new laboratory. The area of the slab was enclosed in a windowed room that was called the slab room bu one and all. The most sensitive test equipment and reference monuments were in that room, but we never had any problems associated with floor stability that I can remember.
A few years ago I was driving by the corner where our old building stood and the building was gone. In its place was a pad ready to have a new building erected. I could not avoid wondering if the contractor that prepared the site of the new building ran into (literally?) our old slab, and if they did, was it removed? How was it removed? For all I know, the slab is still there. Either that, or it cost someone one hell of a lot of money to remove it. It was not an ignorable object. We sure got our money’s worth out of it!